Analysis of variance
The mean values of quantitative traits of five randomly selected plants in each of the RIL and check entries were used for statistical analysis. Mean data for twelve characters were subjected to analysis of variance for experimental design. The mean sum of squares with respect to various morphological traits has been given in Table 1. The analysis of variance as a measure of variability revealed significant differences amongst the RILs for all the characters.
Rao et al., (2006), Singh et al., (2009), Reddy et al., (2011), Hemavathy et al., (2015) and
Dhoot et al., (2017) also reported significant differences for all the characters studied. The existence of satisfactory variability indicated that the RIL population of green gram under research was good enough for further study (Table 1).
GCV and PCV estimates
Phenotypic coefficient of variation (PCV) was found higher than that of genotypic coefficient of variation (GCV) for all the traits, suggesting the role of environmental factors on various characters, also suggested by
Khajudparn and Tantasawat (2011). The genotypes showed significant differences in respect of all the characters studied (Table 2).
Genotypic coefficient of variation (GCV)
GCV ranged from 4.201 per cent (days to 50% flowering) to 46.172 per cent (number of pods per plant). High GCV was observed for number of pods per plant (46.172), seed yield per plant (38.104), number of pods per clusters (32.539), number of cluster per plant (28.514). Number of seeds per pod (12.05), Number of branches per plant (14.925) and plant height (12.563) exhibited moderate GCV. Low GCV was exhibited by 100 seed weight (9.537), days to initial flowering (4.722), Days to maturity (4.291), Days to 50% flowering (4.201) (Table 2).
Phenotypic coefficient of variation (PCV)
The PCV ranged from 7.049 per cent (days to 50% flowering) to 46.254 per cent (number of pods per plant). High PCV was observed for number of pods per plant (46.254), seed yield per plant (38.587), number of pods per cluster (33.078) and number of clusters per plant (28.984). Moderate PCV was noticed in number of seeds per pod (17.716), number of branches per plant (15.617), hundred seed weight (13.77) and plant height (13.408). Days to maturity (8.941), Pod length (8.64) and days to initial flowering (7.375), days to 50% flowering (7.049) exhibited low PCV. (Table 2).
High PCV and GCV estimates for pods per plant, seed yield per plant were reported by
Rao et al., (2006), Raturi et al., (2015), Anand et al., (2016), Garg et al., (2017) and
Parimala et al., (2020). High PCV and GCV estimates for pods per plant was observed by
Talukdar et al., (2020). Moderate PCV and GCV were found for plant height, number of branches per plant, number of seeds per pod and 100 seed weight. Similar results were also observed by
Pandey et al., (2007) and
Nand and Anuradha (2013) for branches per plant,
Rao et al., (2006), Makeen et al., (2007) and
Kumhar and Choudhary (2007) for 100 seed weight.
Mehta et al., (2019) for number of branches per plant. Lowest PCV and GCV estimates were obtained for days to 50% flowering, pod length and days to maturity. These results are in correspondence with
Rao et al., (2006), Makeen et al., (2007), Kumhar and Choudhary (2007),
Nand and Anuradha (2013),
Zuge et al., (2019) and
Asari et al., (2019) for days to 50% flowering and days to maturity.
Perera et al., (2017) for days to maturity. The results obtained for PCV and GCV showed that there is considerable possibility of further improvement and by appropriate selection for these characters and development of high yielding variety can take place. Low values of genotypic and phenotypic coefficient of variation were noted for pod yield, days to maturity and days to 50% flowering which indicated low range of variation for these characters in the genotypes, thus offering little scope for further improvement of these characters through simple selection.
Heritability broad sense (h2)
The heritability broad sense (h
2) ranged from 23.00 per cent (days to maturity) to 99.60 per cent (number of pods per plant). High heritability was observed in number of pods per plant (99.6), seed yield per plant (97.5), number of clusters per plant (96.8), number of pods per cluster (96.80), number of seeds per pod (89.50), plant height (87.8), number of branches per plant (86.5). Moderate heritability was observed in pod length (57.2), hundred seed weight (47.9), days to initial flowering (41.07), days to 50% flowering (35.5). Low heritability was observed for days to maturity (23.0) (Table 2).
Similar results were reported by
Natarajan et al., (1988), Saxena and Singh (2007).
Hemavathy et al., (2015), Garg et al., (2017) for plant height, seed yield per plant and number of pods per plant.
Mehendi et al., (2018) for number of pods per cluster, seed yield per plant.
Zuge et al., (2019) reported high heritability for plant height, number of pods per plant and similarly moderate values were recorded for pod length.
Asari et al., (2019) reported high heritability for plant height, number of pods per plant, number of branches per plant, number of pods per cluster, number of cluster per plant, number of pods per plant, number of seeds per pod and seed yield per plant. These results are in correspondence with the findings of
Reddy et al., (2003) and
Makeen et al., (2007). For reliable selection high heritability of a character needs to be accompanied by high genetic advance
(Johnson et al., 1955) because such characters are mostly controlled by additive gene action. Similar results were obtained by the presence of high heritability indicates preponderance of additive gene action in expression of these traits and they can be improved through individual plant selection.
Genetic advance
A perusal of genetic advance for all the quantitative traits under study ranged from 0.45 per cent (hundred seed weight) to 15.95 per cent (number of pods per plant). Moderate genetic advance was expressed by number of pods per plant (15.95) and remaining parameters observed low genetic advance that is plant height (6.60), number of cluster per plant (3.57), number of seed per plant (3.36), number of pods per cluster (3.18), days to maturity (3.13), days to first flowering (2.75), days to 50% flowering (2.43), seed yield per plant (2.33), number of branches per plant (0.97), pod length (0.74) and hundred seed weight (0.45). (Table 2). Similar results were observed by
Nand and Anuradha (2013) and
Malli et al., (2018) for days to initial flowering, days to 50% flowering, days to full maturity, 100 seed weight and pod length.
Raturi et al., (2015) for plant height and number of branches per plant.
Genetic advance as percent of mean (GAM)
A perusal of genetic advance for all the quantitative traits under study ranged from 4.24 per cent (days to maturity) to 94.94 per cent (number of pods per plant). High genetic advance was observed for the traits
i.e. number of pods per plant (94.94 per cent), seed yield per plant (77.51), number of pods per cluster (65.93), number of clusters per plant (57.78), number of seeds per pod (32.65), number of branches per plant (27.82) and plant height (24.25). Moderate GAM was observed in hundred seed weight (13.60), pod length (10.18). Days to initial flowering (6.22), days to 50% flowering (5.15) and days to maturity (4.24) expressed low GAM. (Table 2).
Similar results were observed by
Manivannan et al., (1996), Pandiyan et al., (2006). Nand and Anuradha (2013) for number of pods per plant, number of seeds per pod, seed yield per plant.
Hemavathy et al., (2015) for plant height, days to 50% flowering, days to maturity, number of cluster per plant, number of pods per cluster, number of pods per plant, hundred seed weight and seed yield per plant.
Asari et al., (2019) for seed yield per plant, number of pods per plant, number of clusters per plant, number of branches per plant and plant height.
High heritability estimates coupled with high or moderate genetic advance was observed for number of branches per plant, number of pods per cluster, number of cluster per plant, number of pods per plant, number of seeds per pod, plant height and seed yield per plant. Similar results were reported by
Baisakh et al., (2016) for plant height and pods per plant.
Muthuswamy et al., (2019) for plant height, number of branches per plant, number of pod per plant, and seed yield per plant.
Pavan et al., (2019) for pods per plant, seed yield per plant, plant height and number of branches per plant.
Asari et al., (2019) for plant height, number of branches per plant, number of cluster per plant, number of pods per plant and seed yield per plant.